This is the third album by The Moritz von Oswald Trio, comprised of members Moritz von Oswald (Basic Channel, Rhythm & Sound), Max Loderbauer (NSI, Sun Electric), and Sasu Ripatti (Vladislav Delay, Luomo). This time, the album is enriched and expanded by guitar contributions from Paul St. Hilaire (also known as Tikiman), and double bass courtesy of Marc Muellbauer (via ECM). Horizontal Structures is palpably a more open, more expressive album than the previous studio recording, Vertical Ascent. There is more contrast, more light and shade. St. Hilaire and Muellbauer add fresh drama and swing to the intimate tonal and rhythmic interactions of the core grouping. The coherence of the five-piece is remarkable; the boundary between acoustic and electronic undone. The group's evolution is firmly signaled in the opener, "Structure 1." There's a lush, romantic quality to the playing and arrangement that has not been heard before: the guitar licks have a bluesy lilt, the bass imparts melody as well as physical presence, the synth sequences are more painterly, looser somehow, and Ripatti's percussion roams feelingly. "Structure 2" is like '70s spy-flick jazz or groove-heavy Krautrock stripped to its barest essence, Loderbauer and von Oswald's electronics glistening in a sticky cobweb of reverb and delay. The languidly stepping "Structure 3" faintly recalls von Oswald's work with Mark Ernestus as Rhythm & Sound, with St. Hilaire's chords hanging thick above bone-dry drum machine drift. Lastly, "Structure 4," the track structurally closest to techno, is pervaded by a sense of mischief, with Muellbauer's strings -- plucked, bowed, scraped -- coming to the fore. For all its complexity, this is also a very playful album, and the Trio's increased confidence and empathy as improvisers allow them to indulge flights of percussive fancy, sudden about-turns, and vectors into the unknown. Horizontal Structures sounds, above all else, free.